Derivative Instruments and Hedging Activities (Fair Value Amounts of Derivative Instruments Reported on our Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	$ 59	$ 41
Fair value of derivative contracts in payable position	4	37
Derivative, notional amount	24,789	38,066
Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	54	1
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	21,223	24,339
Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	5	40
Fair value of derivative contracts in payable position	4	37
Derivative, notional amount	3,566	13,727
Interest rate contracts \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	5	37
Fair value of derivative contracts in payable position	3	37
Derivative, notional amount	3,440	13,546
Interest rate swaps \| Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	16,986	24,203
Interest rate purchased options \| Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	54	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	4,100	0
Interest rate purchased options \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	3	37
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	1,658	6,742
Interest rate futures and forwards \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	17	11
Interest rate written options \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	2	0
Fair value of derivative contracts in payable position	3	37
Derivative, notional amount	1,765	6,793
Foreign exchange contracts \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	3
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	126	181
Foreign exchange forwards \| Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	1
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	137	136
Foreign exchange futures And forwards \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	3
Fair value of derivative contracts in payable position	0	0
Derivative, notional amount	126	181
Equity contract \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	1	0
Derivative, notional amount	0	0
Equity written options \| Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative contracts in receivable position	0	0
Fair value of derivative contracts in payable position	1	0
Derivative, notional amount	$ 0	$ 0

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

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No definition available.

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